One Daily

Research-supported combinations

Ingredient pairs in this product that have synthesised research evidence together.

• Moderate evidenceVitamin E + Vitamin Cfor Reduced Pain· 3 studies

  Across 3 studies, all reported beneficial effects of the combination of vitamin E and vitamin C on pain reduction, with effect sizes ranging from small to moderate (predominantly small). The median study duration was 60 days. The combination shows similar effects to vitamin E or vitamin C alone based on solo syntheses, but all studies tested the combination as part of a multi-ingredient formulation, precluding isolation of the specific contribution of these two vitamins.

• Very low evidenceVitamin D + Vitamin Cfor Improved Cognitive Function· 3 studies

  Of the 3 studies examining the combination of vitamin D and vitamin C for cognitive function, 1 reported a beneficial effect while 2 found neutral effects. The single beneficial finding came from a systematic review that did not isolate the combination, and the other two reviews/meta-analyses found no significant effect. Compared to vitamin D alone (which showed neutral effects across 3 solo studies), the combination evidence is similarly inconclusive. No consistent dose, form, or duration data were reported across studies.